One-Shot Tagging During Wake and Cueing During Sleep With Spatiotemporal Patterns of Transcranial Electrical Stimulation Can Boost Long-Term Metamemory of Individual Episodes in Humans

Abstract

Non-invasive Modulation of Specific Episodes

Closed-Loop tACS Delivered during Slow-Wave Sleep Reduces Retroactive Interference on a Paired-Associates Learning Task

“…We show here that closed-loop tACS protects from retroactive interference in a PAT, specifically for those on the lower half of the encoding spectrum (low-encoders). This work adds to a growing body of research from our laboratory suggesting modulation of the brain via tES improves performance in a variety of tasks, including visual target detection [ 57 , 58 , 81 , 82 , 83 , 84 , 85 ], working memory [ 86 , 87 ], episodic metamemory [ 44 , 45 ], and insight into temporal rules [ 88 ]. These results are encouraging, but future work is needed to better understand the underlying brain mechanisms of stimulation-induced sleep-dependent memory consolidation enhancement and protection from retroactive interference.…”

“…Augmentation of memory consolidation during sleep has previously been explored using pharmacological methods [ 39 , 40 ], auditory stimulation [ 41 ], Targeted Memory Reactivation (TMR; [ 42 , 43 , 44 , 45 ]), and even by physically rocking participants during sleep [ 46 ]. The use of tDCS or tACS during sleep has been shown to improve memory performance in various ways, including recall [ 6 , 47 ] and encoding [ 48 ].…”

A Systematic Review of Closed-Loop Feedback Techniques in Sleep Studies—Related Issues and Future Directions

“…Lastly, there are studies that demonstrate the various applications of closed-loop feedback systems for sleep research. Pilly et al designed a novel tES paradigm for managing sophisticated TMR control during sleep [74]. Using 32 stimulation electrodes, they make 14 types of optimal tES patterns, and these were used for memory encoding and reactivation during sleep when delivery of tES coincides temporally with the up-state of SO.…”

“…Furthermore, in addition to the role of memory consolidation, immune-supportive function [52] or subjective sleep quality [53] were also revealed to be related to slow wave activity by using electrical stimulation. Moreover, applying the TMR technique to the closed-loop feedback system showed the possibility and reliability of memory encoding and memory improvement techniques [65,74].…”

“…For example, Antony et al introduced TMR, which used tone stimulation for closed-loop feedback and verified spindle refractory period on declarative memory consolidation [65]. Pilly et al also suggested a novel memory encoding method using spatiotemporal patterns of tES and introduced TMR for cueing memory with closed-loop tES [74]. They confirmed a reliable effect of memory encoding and cueing during wake and sleep, and they suggested the possibility of a closed-loop tES system for the application of behavioral therapy or as a low-risk non-invasive approach for boosting learning and memory.…”